Non-conducting and waterproof composition and method of manufacturing



' r. sans racran r anion JOHN J. LAING- AND CHARLES W. BOILING, F MADISON, WISCONSIN.

SAME.

memes.

No. Drawing.

Specification of Letters Patent,

Patented May 27, rate.

Application filed February 27, 1919. Serial No. 279,644.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L.,-625.)

T 0 all whom it may concern Be it known that we, JOHN J. LAiNo and CHARLES W. BOLING, citizens of the United States of America, and 1 employees of the 5 Department of Agriculture of the said United States, residing at Madison, in the county of Dane, State of Wisconsin, (whose post-ofiice address is Madison, Wis consin,) have invented new and useful Improvements in Non-Conducting and Waterproof Composition and Methods of Manufacturing Same, of which the following is a specification.

This application is made under the act of March 3, 1883, ch. 143 (22 Stat, 625), and the invention herein described and claimed may be used by the Government of the United States, or any of its officers or employees, in the prosecution of work for the Government or any person in the United States, without payment to us of any royalty thereon.

The object of our invention is the production of a nonconducting and waterproof composition'to be ap lied to the manufacture of molded artic es where waterproof qualities are a first position consists of a mixture of paper pulp or other vegetable fibrous material, and 'a cementing material such as bitumen, pitch, asphalt, shellac, rosin, or similar materials that are hard at ordinary temperatures but which have melting points below the temperature at which the fibrous material is injuriously affected. In preparing the composition we prefer to use about one part, of paper pulp to five arts of pitch, though this maybe varied wit in reasonable limits. It is essential that a pitch which has a melting point of about 221 F. be employed in order consideration. Our comi that the final composition will be able to stand boiling water and still develop the greatest possible amount of strength. In making the composition it is important, in order that the pulp may become thoroughly impregnated with pitch, to. maintain the mixture at a temperature of 300 F. Higher ten'lperature is to be avoided because of the danger of injuring the pulp and diminishing the strength of the resulting material, while the mixing is not satisfactory when carried on at a lower degree of heat. In molding it is also important, in order that a clean out article may be obtained to maintain the molds at a temperature about 150 F. This can be accomplished in jacketed molds commonly used in the art, whereby steam is admitted to the jacket while the object is being formed under pressure and is replaced by cold water to set and harden the o'bject ust before releasing the pressure and opening the mold to remove it.

Our composition is inexpensive, durable and waterproof and, as a whole, possesses in a high degree all the desired properties of a composition for molded articles.

We claim:

A plastic com osition adapted to form a material from which molded articles can be made comprising from one to two pounds of paper pulp and four to ten pounds of pitch. In testimony whereof we aflix our signa= tures in the presence of two subscribing witnesses.

Witnesses L. O. BAXTER,

VANCE T. EDWARDES. 

